System and method for end-to-end threshold setting

ABSTRACT

A system and method for performance monitoring of a telecommunications network that uses a layered performance monitoring structure. First, the monitoring points within the network are identified according to a customer request. The customer request is used to generate a service provisioning request, which indicates the path endpoints and the desired level of service. If the service is a digital data service and is supported for monitoring purposes, the network elements closest to the path endpoints are identified as primary monitoring points and activated, and based upon the desired level of service, a number of intermediate secondary points along the path are also identified but not activated. If the service is not a digital data service but the customer desires monitoring, then monitoring points are similarly identified and activated. Second, an end-to-end threshold is set for each service requiring thresholding per the service provisioning request. Third, previously identified secondary monitoring points are activated in the event that a degradation or failure is detected at the path endpoints. Upon an indication of trouble, the higher performance monitoring layers command the lower layers to perform trouble isolation processing, during which the lower layers determine which secondary monitoring points must be activated to determine the origin of the problem. The higher layers command the lower layers to commence activation.

CROSS-REFERENCE TO OTHER APPLICATIONS

The following applications of common assignee contain some commondisclosure:

"System and Method for Identifying the Technique Used for Far-EndPerformance Monitoring of a DS1 at a Customer Service Unit," filed Jun.25, 1996, U.S. application Ser. No. 08/671,028.

"System and Method for Formatting Performance Data In aTelecommunications System," filed Jun. 26, 1996, U.S. application Ser.No. 08/670,905.

"System and Method for Reported Root Cause Analysis", filed Jun. 28,1996, U.S. application Ser. No. 08/670,844.

"System and Method for Unreported Root Cause Analysis," filed Jun. 28,1996, U.S. application Ser. No.08/668,516.

"Enhanced Correlated Problem Alert Signals," filed Jun. 28, 1996, U.S.application Ser. No. 08/670,848.

"Correlated Problem Alert Signals," filed Jun. 28, 1996, U.S.application Ser. No.08/673,271.

"Raw Performance Monitor Correlated Problem Alert Signals," filed Jun.28, 1996, U.S. application Ser. No. 08/670,847.

"Raw Performance Monitor Correlated Trouble Isolation," filed Jun. 28,1996, U.S. application Ser. No. 08/672,812.

"System and Method for Unreported Trouble Isolation," filed Jun. 28,1996, U.S. application Ser. No. 08/672,513.

"System and Method for Monitoring Point Identification," filed Jun. 28,1996, U.S. application Ser. No. 08/672,512.

"System and Method for Monitoring Point Activation," filed Jun. 28,1996, U.S. application Ser. No. 08/672,356.

"System and Method for Tracking and Monitoring Network Elements," filedJun. 25, 1996, U.S. application Serial No. 08/671,029.

The above-listed applications are incorporated herein by reference intheir entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The following invention relates generally to network management in atelecommunications system, and more specifically toward a system andmethod for (1) identifying monitoring points within a telecommunicationsnetwork, (2) identifying end-to-end threshold levels for measuring andmonitoring circuits, and (3) activating monitoring points whennecessary.

2. Related Art

Telecommunication service providers (e.g., MCI TelecommunicationsCorporation) provide a wide range of services to their customers. Theseservices range from the transport of a standard 64 kbit/s voice channel(i.e., DS0 channel) to the transport of higher rate digital dataservices (e.g., video). Both voice channels and digital data servicesare transported over the network via a hierarchy of digital signaltransport levels. For example, in a conventional digital signalhierarchy 24 DS0 channels are mapped into a DS1 channel. In turn, 28 DS1channels are mapped into a DS3 channel.

Routing of these DS1 and DS3 channels within a node of the network isperformed by digital cross-connect systems. Digital cross-connectsystems typically switch the channels at the DS1 and DS3 signal levels.Transmission of channels between nodes is typically provided viafiber-optic transmission systems. Fiber-optic transmission systems canmultiplex a plurality of DS3 channels into a higher rate transmissionover a single pair of fibers. In one example, signal formats for thefiber-optic transmission systems are defined by the manufacturer. Theseproprietary systems are referred to as asynchronous transmissionsystems.

Alternatively, a fiber-optic transmission system can implement thesynchronous optical network (SONET) standard. The SONET standard definesa synchronous transport signal (STS) frame structure that includesoverhead bytes and a synchronous payload envelope (SPE). One or morechannels (e.g., DS1 and DS3 channels) can be mapped into a SPE. Forexample, a single DS3 channel can be mapped into an STS-1 frame.Alternatively, 28 DS1 channels can be mapped into virtual tributaries(VTs) within the STS-1 frame.

Various STS-1 frames can be concatenated to produce higher rate SONETsignals. For example, a STS-12 signal includes 12 STS-1 frames, while aSTS-48 signal includes 48 STS-1 frames. Finally, after an STS signal isconverted from electrical to optical, it is known as an optical carrier(OC) signal (e.g., OC-12 and OC-48).

An end-to-end path of a provisioned channel within a network typicallytraverses a plurality of nodes. This provisioned channel is carried overtransmission facilities that operate at various rates in the digitalsignal hierarchy. For example, a provisioned DS1 channel may exist aspart of a DS3, VT1.5, STS-1, STS-12, OC-12, and OC-48 signal along partsof the end-to-end path. This results due to the multiplexing anddemultiplexing functions at each of the nodes.

One of the goals of a network management system is to monitor theperformance of the provisioned channel. Performance of the provisionedchannel can include various measures. One measure is the unavailabilityof the provisioned channel. Unavailability is generally defined as theamount (or fraction) of time that a channel is not operational. Variouscauses such as cable cuts can lead to channel downtime. Networkresponses to channel downtime can include automatic protection switchingor various restoration procedures (e.g., digital cross-connectdistributed restoration).

Although unavailability is a major performance measure from a customer'sstandpoint, other performance measures can also be critical. Forexample, if a customer desires a digital data service for thetransmission of financial data, the number of errored seconds orseverely errored seconds may be of concern.

In conventional network management systems, performance monitoring isaccomplished in piecewise fashion. For example, consider a provisionedchannel that traverses an end-to-end path comprising asynchronoustransmission systems and SONET transmission systems. Performancemonitoring information for these two types of transmission systems istypically maintained in separate databases. Moreover, the various typesof transmission systems may be provided by multiple vendors. Each ofthese vendors may define their own separate performance monitoringprocess. For example, the vendor-controlled process may define the typesof data that are retrieved from or reported by the individual networkelements.

In this environment, comprehensive performance monitoring analysis isdifficult to accomplish. What is needed is a network management systemthat can monitor provisioned channels at various points of theend-to-end paths and isolate the source of the problem that is causingthe observable error activity. This capability allows a service providerto proactively address potential problems in network performance,thereby minimizing the impact on the customer's perception of thequality of the provisioned service.

SUMMARY OF THE INVENTION

The present invention is directed to a system and method for enhancingthe performance monitoring system of a telecommunications network.

The first section is directed to a system and method for identifyingmonitoring points within the network according to a customer request. Aservice provisioning request is initiated based on a customer order. Theservice provisioning request designates the required bandwidth and thecustomer endpoints, between which service is to be provided. Inaddition, the provisioning request identifies the level or quality ofservice required for the service. In response to the serviceprovisioning request, a path through the network elements of the networkis determined, thereby defining a circuit topology. If a digital dataservice or any other service that requires monitoring is provisioned,then the process for identifying monitoring points commences. Theprimary monitoring points are identified at the network elements closestto the path endpoints. Secondary monitoring points, representingintermediate monitoring points along the path, are also identified basedupon the level of service required by the service provisioning request.The primary monitoring points are then activated to provide monitoringinformation.

The second section is directed to a system and method for settingmonitoring thresholds for services provisioned by the service provider.Criteria such as the circuit path length and the type of service areused to establish thresholds for a particular service. Each thresholdcan represent an acceptable tolerance level in the quality of serviceprovided, beyond which level a service does not satisfy customerrequirements provided in the service provisioning request. Thesecustomized thresholds are used by the primary and secondary monitoringpoints to determine when a provisioned service experiences unacceptablelevels of degradation.

The third section is directed to a system and method for activatingpreviously identified monitoring points in the event that a degradationor failure is detected at the path endpoints. When a degradation orfailure is detected at the previously activated primary monitoringpoints, this information is provided to the higher layers of theperformance monitoring system. The higher layers then request that thelower layers, which are in direct contact with the network elements,proceed in isolating the network problem. During isolation processing,the lower layers determine which secondary monitoring points must beactivated to determine the origin of the problem. The higher layers areinformed of the secondary monitoring points that must be activated bythe lower layers, and accordingly submit requests for the lower layer toactivate the required monitoring points.

BRIEF DESCRIPTION OF THE FIGURES

The present invention will be described with reference to theaccompanying drawings, wherein:

FIG. 1 illustrates the representative bit rates for a DS0, DS1, and DS3circuits.

FIG. 2 illustrates the multiplexing of DS1 circuits into a DS3 circuit.

FIG. 3 illustrates the physical interfaces of a SONET network.

FIG. 4 illustrates a SONET STS-1 frame.

FIG. 5 illustrates a mapping of digital circuits into an STS-1 frame.

FIG. 6 is a block diagram illustrating the layers of the TMN standard.

FIG. 7 illustrates raw performance measures for typical digitalcircuits.

FIG. 8 is a flow chart illustrating initiation of a service provisioningrequest.

FIG. 9A illustrates the circuit topology between two endpoints along anasynchronous communication path.

FIG. 9B illustrates the circuit topology between two endpoints along anasynchronous-SONET-asynchronous communication path.

FIG. 9C illustrates the circuit topology between two endpoints along aSONET communication path.

FIGS. 10A-10B are flow charts illustrating a monitoring pointidentification process.

FIG. 11 is a flow chart illustrating the process of threshold setting.

FIG. 12 is a flow chart illustrating the dynamic monitoring pointactivation process.

FIG. 13 illustrates a block diagram of a computer useful forimplementing elements of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to an improved system and method forenhancing the performance monitoring capabilities of atelecommunications network management system. Systems and methods arepresented for: (1) identifying monitoring points within the networkaccording to a customer request, (2) setting thresholds for servicesrequired by a customer along a network path, and (3) activatingpreviously identified monitoring points in the event that a degradationor failure is detected at the path endpoints.

A telecommunications network can be divided into a mesh of networkelements interconnected by digital circuits. Together, the networkelements and digital circuits transmit information between customerlocations.

More precisely, digital circuits refer to electrical framing structurescorresponding to particular digital data bit rates. The higher thedigital data bit rate, the more information that can be transmitted by adigital circuit. As shown in Table 1, a DS0 level circuit has a digitaldata bit rate of 0.064 megabits per second (Mbps). This 0.064 Mbpschannel carries a single voice channel. As further illustrated in Table1, a DS1 circuit can carry information at 1.544 Mbps, while a DS3circuit can carry information at 44.736 Mbps. The DS0, DS1, and DS3circuits are defined by the U.S.A. standard, which is also used in thecountries of Australia, Canada and Japan.

                  TABLE 1                                                         ______________________________________                                        USA Standard    CCITT Standard                                                Signal                                                                              Carrier   Rate in Signal   Carrier                                                                             Rate in                                Level System    Mbps    Level    System                                                                              Mbps                                   ______________________________________                                        DS0   --         0.064  CEPT0    --     0.064                                 DS1   T1         1.544  CEPT1    E1     2.048                                 DS3   T3        44.736  CEPT2    E3    34.368                                 ______________________________________                                    

Table 1 also shows the digital bit rate in Mbps for CEPT0-CEPT2circuits, which are used in CCITT countries. Notably, the CEPTI circuit,which has a rate of 2.048 Mbps, is commonly used in North America and isreferred to by its carrier name as an E1 circuit.

The higher the digital bit rate for a circuit, the more information thatcan travel over that circuit. As shown in FIG. 1, 24 DS0s 101-124 aremapped into a single DS1 circuit. In other words, the informationcarried on 24 DS0s can be carried on a single DS1 circuit. Similarly, 28DS1 circuits 125-152 are mapped into a single DS3 circuit 153.

For asynchronous communications over DS-n and CEPT-n digital circuits, apath is defined as a framed digital signal between any two points. Thepath is considered to be independent of the physical transmissionmedium. For asynchronous communications over DS-n and CEPT-n digitalcircuits, a line is defined as the physical transport vehicle thatprovides the means for moving digital information between any twopoints. For example, the line may be represented by a bipolar signaltraversing a metallic transmission medium.

Transmission over an optical fiber network or a digital microwavenetwork is accomplished via proprietary protocols or by a standardizedprotocol known as SONET (synchronous optical network). SONET, which hasbecome the ANSI and ITU standard, is a multi-leveled protocol that isused to transport high-speed signals with circuit switched synchronousmultiplexing.

FIG. 2 shows an M13 multiplexer which receives a series of DS1 circuits201-203 and multiplexes the circuits into a DS3 circuit 205. Instead ofhaving digital bit rates of exactly 1.544 Mbps each as depicted in Table1, DS1 circuits 201-203 typically vary from this amount by a toleranceof ±75 bits per second. To synchronize the asynchronous signalstraversing DS1 circuits 201-203, the M13 multiplexer will add extra bitsin a process known as "bit stuffing."

Because of the extra bits that have been added, an intermediate networknode between the origin and destination of a signal must firstdemultiplex the entire set of channels in order to select a singlechannel. Therefore, an intermediate node attempting to drop a channel oradd a channel from a signal string needs an M13 multiplexer todemultiplex the signal, a patch to cross-connect the signal, and anotherM13 multiplexer to re-multiplex the new signal stream.

Since equipment using the SONET protocol performs synchronousmultiplexing, no bit stuffing is necessary. This promotes visibility oflower rate channels without demultiplexing. Therefore, SONET networkscan use ADMs (add/drop multiplexers) which are capable of extractingonly those channels that are desired, allowing the remainder of thechannels to remain undisturbed.

SONET networks are defined by paths, lines, and sections. A SONET pathis an end-to-end logical link between customer locations. A SONET lineis a connection between two network nodes that multiplex, synchronize,switch, and cross-connect SONET signals. A SONET path comprises one ormore lines. A SONET section is a link between. network elements thatperform signal regeneration, framing, scrambling, and fault locationwithin the network. One or more SONET sections comprise a SONET line.

Table 2 shows the physical interfaces used for a SONET network. An STS(synchronous transport signal) refers to a digital SONET bit rate fortransmission over an electrical medium. An OC (optical carrier) signal,which is a scrambled, optical version of an STS signal, refers to adigital SONET bit rate for transmission over an optical medium. Table 2identifies an STS-1 and OC-1 frames as having a digital bit rate of51.84 Mbps, STS-3 and OC-3 frames as having a digital bit rate of 155.52Mbps, STS-12 and OC-12 frames as having a digital bit rate of 622.08Mbps, and STS-48 and OC-48 frames as having a digital bit rate of2488.32 Mbps. Higher rate SONET signals are also contemplated in thepresent invention.

                  TABLE 2                                                         ______________________________________                                        Synchronous    Optical Carrier                                                                          Line Rate                                           Transport Signal                                                                             Designations                                                                             in Mbps                                             ______________________________________                                        STS-1          OC-1        51.84                                              STS-3          OC-3       155.52                                              STS-12         OC-12      622.08                                              STS-48         OC-48      2488.32                                             ______________________________________                                    

FIG. 3 illustrates exemplary network elements and digital circuits in aSONET network. LTEs (line terminating elements) 302, 305, 307, 310 aremultiplexers used to terminate lines 340-345. STEs (section terminatingelements) 303, 304, 308, 309 are regenerators that boost signals thathave been attenuated by transmission over the optical fiber. SAE (SONETaccess element) 301 is a multiplexer used to multiplex DSI circuit 320and DS3 circuit 321 into an OC-12 fiber optic connection 322. BBDCS(broad band digital cross-connect system) 306 provides directsynchronous switching at a cross-connect speed (matrix speed) of anSTS-1 frame. WBDCS (wide band digital cross-connect system) 311 providesdirect synchronous switching at a cross-connect speed (matrix speed) ofa VT 1.5 frame (a portion of an STS frame, as defined below).

The SONET path 350 between a customer connected to SAE 301 and WBDCS 311comprises the following SONET lines and sections:

(1) line 340 between SAE 301 and LTE 302 over OC-12 circuit 322;

(2) line 341 between LTE 302 and LTE 305 comprising:

(a) section 330 between LTE 302 and STE 303 over OC-48 circuit 323;

(b) section 331 between STE 303 and STE 304 over OC-48 circuit 323;

(c) section 333 between STE 304 and LTE 305 over OC-48 circuit 323;

(3) line 342 between LTE 305 and BBDCS 306 over OC-12 circuit 324;

(4) line 344 between LTE 307 and LTE 310 comprising:

(a) a section 333 between LTE 307 and STE 308 over an OC-48 circuit 326;

(b) a section 334 between STE 308 and STE 309 over an OC-48 circuit 326;

(c) a section 335 between STE 309 and LTE 310 over an OC-48 circuit 326;

(5) line 345 between LTE 310 and WBDCS 311 over an OC-12 circuit 325;

FIG. 4 shows a SONET STS-1 frame in detail. The STS-1 frame comprises atransport overhead and an SPE (synchronous payload envelope). Thetransport overhead comprises a section overhead 401 and a line overhead402. The SPE comprises a path overhead 403, seven groups of data knownas VTs (virtual tributaries), and a group of packing bytes 405 at theend of the VT groups.

Referring to FIG. 3, section overhead 401 is inserted and extracted atSTEs 303, 304, 308, 309 and LTEs 302, 305, 307, 310, and BBDCS 306. Lineoverhead 402 is inserted and extracted at the line endpoints, includingLTEs 302, 305, 307, 310, and BBDCS 306. Path overhead 403 is insertedand extracted only at the path endpoints, represented by SAE 301 andWBDCS 311.

The actual data being transmitted can be carried in the VT groups, whichare shown in greater detail in FIG. 5. A complete STS-1 payloadcomprises seven VT groups. The seven VT groups of an STS-1 payload cancarry the equivalent information of a DS3 circuit. The VT groups canalso be subdivided into subgroups. For example, VT1.5 502 canaccommodate DS1 circuit 501. Similarly, VT2 503 can accommodate E1circuit 504. Table 3 shows the VT types, their bit rates in Mbps, andthe corresponding circuits which they can respectively accommodate.

                  TABLE 3                                                         ______________________________________                                                                 Circuits Which                                       VT (Virtual              can be                                               Tributary) Type                                                                             Rate in Mbps                                                                             Accommodated                                         ______________________________________                                          VT1.5       1.728      DS1                                                  VT2           2.308      E1                                                   VT6           6.912      DS2                                                  ______________________________________                                    

Under the performance monitoring standard known as ITU-TMN(International Telecommunications Union--Telecommunications ManagementNetwork), network performance management is enhanced by providingnetwork users remote access to the network. Referring to FIG. 6, theITU-TMN performance management standard comprises five layers:

(1) network element layer (NEL) 600,

(2) element management layer (EML) 610,

(3) network management layer (NML) 620,

(4) service management layer (SML) 630,

(5) business management layer (BML) 640.

As shown in FIG. 6, the NEs consists of a plurality of network elements(NEs) 601-606. NEs 601-606 represent the physical portion of thetelecommunications network. As mentioned above, the network elementsinclude LTEs, STEs, SAEs, BBDCSs and WBDCSs, inter alia.

NEs 601-606 collect PM information for particular digital bit rates(e.g., DS1, DS3, E1, STS-N and OC-N). NEs 601-606 use error calculationmethods to provide performance data on the facilities (circuits) thatare provisioned through them. NEs 601-606 also provide different errorcalculation methods for the various digital bit rates.

FIG. 7 shows the typical raw performance measures for well-known digitalbit rates. A cyclic redundancy check (CRC) is used to extract raw errorperformance data for a DS1 circuit. A parity check is used to extractraw error performance data for a DS3 circuit. A bit interleaved paritycheck is used to extract raw error performance data for a VT-n circuit.The raw performance data is processed by the NEs into the measurementsof primitives and failures.

Primitives comprise anomalies and defects. An anomaly gives a measure ofthe discrepancy between the actual and desired characteristics of amessage. Typical anomalies are bit error detection events andsynchronization-related events. For example, a bit error detection eventrefers to a situation where a bit is transferred from a source to adestination within the correct assigned time slot, but the bit that isdelivered is different from the value that was originally sent from thesource.

A defect refers to some limited interruption in the ability of atelecommunications facility to perform a desired function. Hence, anysuccessive anomalies causing a decrease in the ability of a facility toperform a required function result in a defect. Typical defects includeloss of signal (LOS), and severely errored frame (SEF).

LOS occurs for a DS1 line interface when 175±75 contiguous pulsepositions are detected, with no pulses having either positive ornegative polarity. The severely errored frame (SEF) measure refers tothe frequency of occurrence of an error in the bit position known as theframing bit for a particular timing window. For a DS1 circuit, an SEFdefect is the occurrence of two or more frame bit errors in a window(which has a duration of 0.75 ms or 3.0 ms).

A failure refers to the complete termination in the ability of atelecommunications facility to perform a designated function. Failurescan be local failures or remote failures. Local failures includenear-end loss of frame (LOF) and near-end loss of signal (LOS). For aDS1 circuit, a near-end LOF failure is observed when an OOF (out offrame) defect persists for a period of 2.5±0.5 seconds (unless if analarm indication signal (AIS) defect or failure is present). For a DS1circuit, a near-end LOS signal is declared when an LOS defect persistsfor a period of 2.5±0.5 seconds.

It should be noted that different network telecommunications facilitiesmay have different types of performance measures. For example, an STS-1path uses the LOS failure measure, similarly to a DS1 circuit, but italso includes such measures as STS-path loss of pointer (LOP-P), linealarm indication signal (AIS-L), and STS-path AIS (AIS-P).

Referring to FIG. 6, the element management layer (EML) 610 compriseselement managers (EMs) 611, 612. Each of the NEs 601-606 are connectedto one of the EMs 611, 612 in the EML 610. For example, NEs 601-603 areconnected to EM 611. In this manner, each network EM 611, 612 controls aportion of the physical network embodied in the NEL 600.

EMs 611, 612 can retrieve information from NEs 601-606 periodically orupon a user request. Alternatively, NEs 601-606 can be programed toprovide EMs 611, 612 with a predefined subset of network managementinformation at predefined time intervals. The domain of an EM 611, 612can be defined by the vendor. In some situations, the domain of an EM611, 612 is dictated by the geography in which NEs 601-606 reside.

After network management information is acquired by EMs 611, 612 fromNEs 601-606, it is forwarded to the network management layer (NML) 620.NML 620 comprises network manager (NM) 621. NM 621 is logically shown asa single entity. In implementation, NM 621 can comprise one or moresites. For example, multiple service centers (not shown) can exist atdifferent parts of the country (e.g., east coast and west coast). Incombination, these national-level service centers combine to providetotal visibility of the physical network in NEL 600. NM 621 can also besplit among services and/or NEs. For example, a first NM may bededicated to asynchronous parts of the network, a second NM may bededicated to DS1, DS3 and VT-n traffic, and a third NM may be dedicatedto STS-n and OC-n traffic.

Generally, the logical entity identified as NM 621 is a resource that isaccessed by applications in the service management layer (SML) 630. InFIG. 6, SML 630 is shown to include five applications 631-635.Specifically, SML 630 includes configuration/provisioning application631, accounting/billing application 632, security application 633,network performance application 634, and fault management application635. This listing of applications is provided without limitation. Anyother application that utilizes network management data stored withinNEL 600 can also be included. Note that applications 631-635 can also beincluded in NML 620.

Configuration/provisioning application 631 provides a customer interfacefor the provisioning of various services. For example, a customer canindicate a desire for a DS1 digital data service between NE 601 and NE605. Upon receipt of this customer request, provisioning application 631relays the provisioning commands to NM 621. NM 621 then communicateswith EMs 611, 612 and any other EMs that control a part of theend-to-end path to set up the DS1 connection from NEs 601-605.

Applications 632-635 can similarly support a customer interface byproviding access to billing information, security information,performance information and fault management information, respectively.Each of these applications also access the resources that are storedwithin NM 621.

Finally, the network management system also includes business managementlayer (BML) 640. BML 640 includes logical entity 641. Logical entity 641represents the general corporate policy of the network managementsystem. Corporate policy 641 dictates the general business andcontractual arrangements of the service provider.

Having identified the layers of a network management system, themonitoring aspects of the network management system are now described.

Monitoring Point Identification

A first aspect of the present invention is directed to a system andmethod for identifying the monitoring points of a telecommunicationsnetwork.

FIG. 8 shows a flow chart for initiation of the service provisioningrequest. In step 801, SML 630 waits for a service provisioning request.In this state, SML 630 waits for an order entry request from a customerrequesting a telecommunications service.

In step 802, a service provisioning request is prepared by SML 630. Acustomer request is received by a telecommunications customerrepresentative. The subsequent order entry is prepared into a serviceprovisioning request by an SML 630 order entry application system (notshown). The service provisioning request specifies the connection andlevel of service required by the customer. Referring to FIG. 6, theservice provisioning request may designate a connection between acustomer having computers connected to NE 601 and NE 606.

In step 803, the circuit topology is retrieved. In response to thecustomer provisioning request, SML configuration management application631 submits a request to NML 620 to determine the possible network pathsthat may be provisioned through the network.

Specifically, SML configuration management 631 submits a request to theNML 630 configuration management (not shown) to retrieve the circuittopology of the entire network. Since NML 630 has a full view of theentire network, NML 630 configuration management provides the requiredinformation to SML configuration management 631 via the configurationreporting task.

As part of its configuration reporting task, each EM 611, 612configuration manager (not shown) continually updates the NMLconfiguration management to make it aware of the status of the NEs601-606 in its respective domain.

Monitoring points can be identified for a variety of paths throughvarious network elements. FIGS. 9A-9C illustrate examples of paths thattraverse asynchronous and SONET network elements.

FIG. 9A shows an exemplary circuit topology between endpoints E1 900 andE2 901 along an asynchronous communication path. E1 900 is connected toE2 901 via a series of network elements and digital circuits. E1 900 isdirectly connected to M13 multiplexer 902, and E2 901 is directlyconnected to M13 multiplexer 914.

The asynchronous communication path between M13 multiplexer 902 and M13multiplexer 914 is described as follows. An asynchronous DS3 circuit isoutput from M13 multiplexer 902 to digital cross-connect system (DSX-3)904. DSX-3 904 provides a routing function for multiple asynchronous DS3circuits with the node in which it resides. DSX-3 904 then sends theasynchronous DS3 circuit to asynchronous LTE (ALTE) 905. An asynchronousfiberoptic link of line rate n connects ALTE 905 to ALTE 906. After ALTE906 demultiplexes the received signal, the DS3 is passed to DSX-3 908.The asynchronous DS3 circuit then traverses a path through ALTE 910,ALTE 911, DSX-3 912 and M13 914.

FIG. 9B shows an exemplary circuit topology between endpoints E1 900 andE2 901 along a hybrid path, i.e., via an asynchronous-SONET-asynchronouscommunication path. In this example, a DS3 circuit traverses M13 920,DSX-3 922, a first asynchronous system divided by ALTEs 923 and 924,BBDCS 925, a SONET system defined by SLTEs 926 and 927, DSX-3 928, and asecond asynchronous system defined by ALTEs 929 and 930, DSX-3 931 andM13 933.

FIG. 9C shows an exemplary circuit topology between endpoints E1 900 andE2 901 along a SONET communication path. Specifically, the SONET pathcan be described as follows. First, it should be noted that E1 900 isconnected to WBDCS 940 and E2 901 is connected to WBDCS 948, which arenetwork elements capable of providing access to a SONET network (as areSLTEs, inter alia). A SONET OC-12 fiberoptic link connects WBDCS 940 toBBDCS 941. A SONET OC-12 fiberoptic link connects BBDCS 941 with LTE942. A SONET OC-48 fiberoptic link connects LTE 942 with LTE 943. ASONET OC-12 fiberoptic link connects LTE 942 with BBDCS 944. A SONETOC-12 fiberoptic link connects BBDCS 944 with LTE 945. A SONET OC-48fiberoptic link connects LTE 945 with LTE 946. A SONET OC-12 fiberopticlink connects LTE 946 with BBDCS 947. A SONET OC-12 fiberoptic linkconnects BBDCS 947 with WBDCS 948.

The performance monitoring task provided by the NEs functions at threedifferent levels: (1) at the level of the physical entities (electricalor photonic), (2) at the level of the facilities over whichcommunication is established across the path, and (3) at the level offunction of the NEs within the path.

For an asynchronous connection, NE monitoring at the physical entitieslevel and the functional level are combined by definition. Monitoring atthe line level refers to monitoring at the physical entities level,e.g., monitoring of the bipolar signal traversing the metallictransmission medium. However, monitoring at the path level refers to themonitoring of the framed digital signal between endpoints E1 900 and E2901 without regard to the physical connection between endpoints E1 900and E2 901.

For a SONET connection, monitoring at the physical entities level refersto monitoring at the media connecting two facilities together. For anOC-n signal, monitoring occurs in an optical medium. For an STS-nsignal, monitoring occurs in an electrical medium.

For both asynchronous and SONET connections, NE monitoring at thefacility level refers to monitoring at the digital bit rates over whichcommunication is established, e.g., DS1, DS3, VT-n, STS-n, inter alia.An error event detected at a higher bit rate is not necessarilydetectable at a lower bit rate in the digital bit rate hierarchy. Forexample, bursty errors at a higher bit rate may affect only some of thelower bit rates, while a continuous error stream may affect all thelower bit rates. For this reason, performance is monitored at thevarious bit rates separately.

For a SONET connection, monitoring at the functional level occurs at theline, section, and physical levels. Monitoring at the path level refersto monitoring information in the path overhead 403 (shown in FIG. 4).Monitoring at the line level refers to monitoring information in theline overhead 402. Monitoring at the section level refers to monitoringinformation in the section overhead 401.

Having identified various circuit topologies that can be monitored andthe performance monitoring tasks, a monitoring point identificationprocess is now described with reference to FIGS. 10A-10B.

In step 1001, the SML configuration manager 631 determines whether thedigital circuit requested by the customer is a DS0 circuit. Sinceperformance monitoring is not supported for DS0 circuits, adetermination that the circuit specified in the service provisioningrequest is a DS0 circuit (step 1002) will halt processing and result ina return by SML 630 to the state of waiting for a service provisioningrequest in step 1003.

Referring to the exemplary circuit topologies of FIGS. 9A-9C, if acustomer desires a connection between endpoints E1, E2 such that only aDS0 connection is provided between the endpoints, then performancemonitoring would not be supported for that service provisioning request.

In step 1004, the SML configuration manager 631 determines whether theservice type requested in the service provisioning request is a DS1,DS3, VT-n, or an STS-n service (where n is a parameter designating thebit rate of the connection). If SML configuration manager 631determines, at step 1004, that the service provisioning requestindicates an acceptable service type, then SML 630 processing of theservice provisioning request continues to step 1005. If SMLconfiguration manager 631 determines, at step 1004, that it is anunacceptable service type, then SML 630 processing of the serviceprovisioning request is halted and SML 630 returns to the state ofwaiting for a service provisioning request in step 1003.

In step 1005, SML 630 determines whether the service provisioningrequest specifies a DDN (digital data network) service. Since digitaldata services such as video require a high level (quality) of service,performance monitoring is always required for digital data services. Incontrast, voice channels seldom require such high levels of service andwill not be monitored unless specified by the customer in the serviceprovisioning request. If the service provisioning request indicates thata digital data service is required, then processing continues to step1006. At step 1006, monitoring is presumptively required. Otherwise, ifthe service provisioning request indicates that a digital data serviceis not required, then processing continues to 1011 of FIG. 10B.

In step 1007, SML 630 retrieves the level of service requirements fromthe service provisioning request. The level of service requirementsdetermine the quality of service that is to be assigned to the servicerequested in the service provisioning request. The higher the level ofservice required, the greater the number of monitoring points that willbe assigned between endpoints E1 900 and E2 901 in the asynchronous(FIG. 9A), hybrid (FIG. 9B), and SONET (FIG. 9C) communication paths.

In step 1008, SML configuration manager 631 retrieves the circuittopology and assigns all of the required monitoring points. Asexemplified in FIGS. 9A-9C, the circuit topology refers to all possiblecommunication paths between endpoints E1 900 and E2 901, such endpointsE1 900, E2 901 being designated in the service provisioning request.

SML configuration manager 631 also submits a request to the NML 620configuration manager to retrieve the loc(PMPs). PMPs are the monitoringpoints (PMPs). PMPs are the monitoring points that are closest to theendpoints E1 900 and E2 901 for the communication path connecting theseendpoints. For an interexchange carrier (IXC) (e.g., MCITelecommunications Network) which connects local exchange carrier (LEC)facilities together, a PMP may be located at the point of demarcationthat distinguishes the two different networks. PMPs must be designatedif any performance monitoring is to occur. Accordingly, the NML 630configuration manager will always submit the locations of the PMPs tothe SML.

Referring to FIG. 9A (showing an asynchronous path), M13 multiplexer 902and M13 multiplexer 914 are NEs to which the endpoints E1 900 and E2 901are connected. M13 multiplexer 902 and M13 multiplexer 914 lackmonitoring capability. Accordingly, SML 630 assigns PMP function to DS3monitoring units (MUs) 903, 913. Specifically, DS3 MUs 903, 913 monitorthe DS3 circuits at points between (1) M13 multiplexer 902 and DSX-3904, and (2) M13 multiplexer 914 and DSX-3 912.

Referring to FIG. 9B (showing an asynchronous-SONET-asynchronous hybridpath), M13 multiplexer 920 and M13 multiplexer 933 are NEs to which theendpoints E1 900 and E2 901 are connected. Because M13 multiplexer 920and M13 multiplexer 933 similarly lack monitoring capability, SML 630assigns PMP function to DS3MUs 921, 932. As shown, DS3 MUs 921, 932monitor the DS3 circuits at points between (1) M13 multiplexer 920 andDSX-3 922, and (2) M13 multiplexer 933 and DSX-3 931.

Referring to FIG. 9C (showing a SONET path), endpoints E1 900, E2 901are connected to high speed switches WBDCS 940 and WBDCS 948.Accordingly, SML 630 can assign PMP function to WBDCS 940 and WBDCS 948.However, SML 630 can also assign PMP functions to BBDCS 941 and BBDCS947, respectively.

The fact that more than one set of NEs may have PMP capability, asillustrated in FIG. 9C, is another important aspect of the presentinvention. Since more than one NE may have PMP capability, i.e., theability to extract monitoring information near the endpoints E1 900, E2901, the PMPs may be identified by order of preference. Since WBDCSs940, 948 are closest to the endpoints E1 900, E2 901, these PMPs aredesignated as PMP A. Similarly, since BBDCSs 941, 947 are the PMPsfarther away from the endpoints E1 900, E2 901, these PMPs aredesignated as PMP B.

Based on the level of service required by the customer in the serviceprovisioning request, (see step 1007 above) SML 630 will determine thenumber of secondary monitoring points (SMPs) that are to providemonitoring information between the endpoints of the path. SMPs are NEsserving as intermediate performance monitoring data collection pointslocated between endpoints E1 900 and E2 901. As noted above, the greaterthe level of service required by the customer in the serviceprovisioning request, the greater the number of SMPs that willeventually be activated to perform trouble isolation if a defect orfailure is detected. In a preferred embodiment, a transmission facilitywill usually have two SMPs located between the PMPs.

Referring to FIG. 9A (showing an asynchronous path), DS3 MUs 907 and 909can be assigned as SMPs at the points between ALTE 906 and DSX-3 908,and between DSX-3 908 and ALTE 910, respectively.

Referring to FIG. 9B (showing an asynchronous-SONET-asynchronous hybridpath), BBDCS 925 and SLTE 927 can be assigned as SMPs at intermediatepoints along the path.

Referring to FIG. 9C (showing a SONET), if WBDCSs 940, 948 are assignedas the PMPs, then BBDCS 941, BBDCS 944, and BBDCS 947 can be assigned asthe SMPS. However, if BBDCSs 941, 947 are assigned as the PMPs, thenonly BBDCS 944 can be assigned as an SMP.

SML configuration manager 631 must submit a request to the NML 620configuration manager to assign an appropriate number of SMPs along thedesired path. As part of its configuration reporting task, NML 620submits requests to the EML 610 configuration management to assign theappropriate SMPs along the desired path.

More specifically, NML 620 configuration manager submits a request tothe appropriate EMs 611, 612. If the connection path is betweenendpoints E1 900, E2 901 at NE 601 and NE 603, only the configurationmanager for EM 611 receives the request because NE 601 and NE 603 sharethe EM 611 domain. However, if the connection path is between endpointsat NE 601 and NE 606, the configuration managers of both EM 611 and EM612 receive activation requests.

It should be noted that as part of its configuration reporting task, EML610 reports the status of the monitoring points to NML 620, i.e.,indicating whether the SMPs chosen by SML 630 were correctly assigned.When new NEs are connected along the path between the endpoints, (whichwere determined from the service provisioning request) the EML 610report scheduling task schedules the reporting by the new NEs to the NML620 configuration manager. The NML 620 configuration manager reports theidentification status of the SMPs to SML configuration manager 631. Thisincludes the status of any new NEs reported from the lower layer, i.e.,from EML 610.

In step 1009, SML configuration manager 631 issues a request to NML 620for activation of the PMPs. The NML 620 configuration manager routes therequest to EML 610 to activate the PMPs. The activated PMPs monitor thepath derived from the service provisioning request for degradations andfailures. Threshold levels for the PMPs are also set during theiractivation, as described in the Threshold Setting section below.

Returning to step 1005, if it is determined that a service request doesnot involve a DDN service, then the process continues to step 1011 ofFIG. 10B. At step 1011, a further determination is made as to whethermonitoring is still required. If the service provisioning requestindicates that no monitoring is required, then the monitor pointidentification process is halted and the SML returns to the state ofwaiting for a new service provisioning request.

However, if monitoring is required in step 1011 because the serviceprovisioning request indicates that monitoring is required, then SML 630processing continues to steps 1013-1016. In steps 1013-1016, monitoringpoint identification is processed in a similar manner to steps1006-1009.

Threshold Setting

Thresholds, which represent error tolerance levels, provide a method forthe monitoring points to determine when they should report a problem.Threshold setting between the path endpoints, i.e., end-to-end thresholdsetting, exists at two levels: (1) reporting general error activity in aparticular monitoring period using, for example, the measures of erroredseconds (ESs), severely errored seconds (SESs), and unavailability (of aconnection), and (2) reporting to an EM the existence of a potentialproblem, so that trouble isolation can be initiated.

The setting of end-to-end threshold levels is performed based on acustomer request (i.e., in the service provisioning request). For PMPs,the threshold levels are typically set when the PMPs are activated.(Refer to Monitoring Point Identification section above.) For SMPs, thethreshold levels are typically set when the SMPs are activated. (Referto Monitoring Point Activation section below.)

FIG. 11 shows a flow chart demonstrating threshold processing. In step1101, SML configuration manager 631 determines whether the digitalcircuit requested by the customer is a DS0 circuit. Since setting ofend-to-end thresholds is not supported for DS0 circuits, a determinationthat the circuit specified in the service provisioning request is a DS0circuit (step 1101) will halt processing and result in a return by SML630 to the state of waiting for a service provisioning request (step1103).

In step 1105, SML configuration manager 631 determines whether theservice provisioning request requires setting of end-to-end thresholds.If no thresholding is required, then SML 630 processing of the serviceprovisioning request is halted and SML 630 returns to the state ofwaiting for a service provisioning request (step 1103).

Contrarily, if in step 1105 SML configuration manager 631 determinesthat thresholding is required, then SML 630 must determine whethermonitor points have been identified for the path in step 1106. Ifmonitoring points have not been identified, then SML configurationmanager 631 commences monitoring point identification as provided instep 1107. Here, the SML configuration management commences the processof identifying the monitoring points as provided in the monitoring pointidentification process described above.

If the monitoring points have already been identified at step 1106, orif the SML 630 monitoring point identification process is commenced instep 1107 and completed, then end-to-end threshold setting is commencedin step 1108.

In step 1108, the threshold values for the monitoring points are derivedfrom: (1) the endpoints E1 900 and E2 901, (2) the end-to-end servicequality (i.e., service level), and (3) the circuit path length (whichrepresents the physical distance between endpoints E1 900 and E2 901),all three parameters of which are identified in the service provisioningrequest.

Accordingly, in step 1109, the service provisioning request is used toretrieve the threshold values from the threshold value table. Forexample, parameters provided by the user in the service provisioningrequest can be used as an index to retrieve threshold values from athreshold value table. Note that the circuit path length can be derivedfrom an approximation formula based upon the endpoints and the circuittopology.

More specifically, threshold levels are set at both the PMPs and theSMPs. A threshold level for a particular monitoring point, whether thatmonitoring point be a PMP or an SMP, is derived by apportioning thecustomer's desired end-to-end service quality along the approximateddistances separating the monitoring points.

As an example, a customer may desire 20 T1s (which use DS1 levelservice) along the hybrid (asynchronous-SONET-asynchronous)communication path of FIG. 9B with a service level that is 99 percenterror free and 99.9 percent available. The same customer may desire 20T1s along the asynchronous communication path of FIG. 9A at a standardtariff level of service, which is 95 percent error free and 99 percentavailable.

If the PMPs are to be activated at the end of the Monitoring PointIdentification process, or if the SMPs are to be activated at the end ofthe Monitoring Point Activation process, three parameters are used toderive the acceptable thresholds for the first and second desiredservices: (1) the desired endpoints E1 900 and E2 901, (2) theend-to-end service quality derived from the customer's service request,i.e., translating the customer's desired service levels into themeasures of ES, SES, and unavailability, inter alia and (3) the circuitpath length, derived from an approximation based upon the endpoints andthe circuit topology.

SML configuration manager 631 can symbolically designate the firstservice as service A and the second service as service B. Based on theabove-mentioned parameters, SML configuration manager 631 sets thethreshold measures for each service. More specifically, SMLconfiguration manager 631 sets the threshold measures for eachmonitoring point (e.g., PMP or SMP) along the path of a desired service.In other words, the respective values of the ES, SES, unavailability,inter alia threshold measures will be stored at the monitoring pointsalong the path of services A and B.

In this same manner, a customer can specify an arbitrary number ofthreshold measures (e.g., ES, SES, unavailability, inter alia) for eachservice connection desired via the service provisioning request. SMLconfiguration manager 631 can store these values in table format. SMLconfiguration manager 631 receives reports from the lower layersindicating when the pre-set threshold values have been surpassed. SMLconfiguration manager 631 may then decide to reconfigure the servicethrough different circuits and NEs by submitting a request to the NMLconfiguration management.

Once the process of setting of end-to-end thresholds is completed, theSML returns to the state of waiting for another service provisioningrequest in step 1110.

Significantly, as NE sensors report information upward through thehigher performance monitoring layers, the instant invention permits EML610 and NML 620 to set threshold values for the monitoring points thatare different from the threshold values set by SML 630. Typically, thehigher the performance monitoring layer, the higher the threshold thatis set. The reason for this is that ideally, it is preferable to detecterror activity that may escalate to the threshold level set at SML 630,i.e., the threshold level derived from the customer's required level ofservice, before the SML threshold level is actually surpassed.

For example, NML 620 may set its threshold level at twenty percent belowthe SML 630 threshold level, (which was derived as explained above)while EML 610 may set its threshold level at twenty percent below theNML 620 threshold level. In this manner, threshold level setting ishandled proactively by the different performance monitoring layers.

Monitoring Point Activation

As noted above, the PMPs are normally activated for monitoring theperformance of the service designated as a result of the serviceprovisioning request. However, when a failure or degradation is detectedat the PMPs, the SML configuration management must perform performancemonitoring/fault isolation to detect the origin of the problem.

Monitoring point activation is a function of the facilities (e.g.,digital circuits) used and the services provided on the facilities.Depending on the facilities used and the services provided thereon,detection of a failure at the monitoring points and subsequentactivation of the monitoring points may be commenced by EML 610, NML620, or SML 630.

FIG. 12 illustrates an example of a monitoring point activation that iscontrolled by SML 630 when a problem is detected. SML 630 typically hascontrol over monitoring point failure detection and monitoring pointactivation for a path connection between customer premises, i.e., adedicated line for a single customer.

In step 1201, a degradation or failure is detected on a PMP. Each EM611, 612 of the EML 610 has knowledge of the activated NEs within itsrespective domain and submits regular reports regarding the status ofthe activated monitoring point NEs within its respective domain to NML620, as part of its performance monitoring reporting task, which isforwarded to SML 630.

In step 1202, SML 630 determines the existence of a problem detectedfrom the performance monitoring reports forwarded by EML 610. A typicalreported error event reported to SML 630 is a threshold crossing alert(TCA), an alert indicating that a performance monitoring parameter hasexceeded a predefined threshold. In this manner, SML 630 (which has afull view of the service path for the customer-requested connection) ismade aware of any degradations or failures detected at the PMPs throughEML 610.

In step 1203, SML 630 determines that trouble isolation process mustbegin in order to determine the location of the origin of the defectalong the path. During trouble isolation processing, SML 630 determinesthe highest signal transport layer experiencing error activity andidentifies theoriginator oat is the originator of the error activity.Specifically, NML 630 determines whether the monitoring points upstreamof the monitoring point that reported the TCA have reported similar TCAsor non-zero error activity.

In step 1204, if SML 630 determines that an SMP must be activated, itforwards a request for activation to NML 620. NML 620 issues a requestto EML 610 to activate the SMPs during isolation processing as part ofits configuration reporting task. Typically, all the SMPs are activatedsimultaneously for trouble isolation processing, though the SMPs may beturned on sequentially for special processing. SML 620 may also task aportion of the isolation processing to the lower layers.

This process can be repeated until the location of the degradation orfault is determined. Note that the dynamic nature of the activationprocess optimizes the amount of error activity that is reported to thenetwork management layers. In other words, heightened visibility of theperformance of network elements in the network is enabled only when itis needed.

As mentioned, failure detection and monitoring point activation can alsobe controlled by NML 620. NML 620 typically has control over monitoringpoint failure detection and monitoring point activation for a pathconnection used by multiple customers across the backbone of thenetwork. The resulting process is the same as the process described inFIG. 12, except that NML 620 (instead of SML 630) detects the failureand initiates monitoring point activation.

Note that threshold levels for the SMPs are also set during theiractivation, as described in the Threshold Setting section above.

An Embodiment for Implementing the Invention

In one embodiment, the invention is directed to a computer systemoperating as discussed herein. For example, functions in each of thenetwork management layers 600-640 are implemented using computersystems. An exemplary computer system 1302 is shown in FIG. 13. Thecomputer system 1302 includes one or more processors, such as processor1304. The processor 1304 is connected to a communication bus 1306.

The computer system 1302 also includes a main memory 1308, preferablyrandom access memory (RAM), and a secondary memory 1310. The secondarymemory 1310 includes, for example, a hard disk drive 1312 and/or aremovable storage drive 1314, representing a floppy disk drive, amagnetic tape drive, a compact disk drive, etc. The removable storagedrive 1314 reads from and/or writes to a removable storage unit 1316 ina well known manner.

Removable storage unit 1316, also called a program storage device or acomputer program product, represents a floppy disk, magnetic tape,compact disk, etc. As will be appreciated, the removable storage unit1316 includes a computer usable storage medium having stored thereincomputer software and/or data.

Computer programs (also called computer control logic) are stored inmain memory and/or the secondary memory 1310. Such computer programs,when executed, enable the computer system 1302 to perform the featuresof the present invention as discussed herein. In particular, thecomputer programs, when executed, enable the processor 1304 to performthe features of the present invention. Accordingly, such computerprograms represent controllers of the computer system 1302.

In another embodiment, the invention is directed to a computer programproduct comprising a computer readable medium having control logic(computer software) stored therein. The control logic, when executed bythe processor 1304, causes the processor 1304 to perform the functionsof the invention as described herein.

In another embodiment, the invention is implemented primarily inhardware using, for example, a hardware state machine. Implementation ofthe hardware state machine so as to perform the functions describedherein will be apparent to persons skilled in the relevant art(s).

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the relevant art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the invention.

What is claimed is:
 1. A method of setting end-to-end thresholds formeasuring and monitoring circuits in a telecommunications network,comprising the steps of:(1) receiving a service provisioning requestidentifying termination points and a level of service identifying aquality of service desired by a customer; (2) identifying a pathtopology for a provisioned channel between said termination points, saidprovisioned channel having said level of service; (3) if one or moremonitoring points for monitoring a performance of said circuits have notbeen preassigned for said provisioned channel, assigning one or moremonitoring points for monitoring a performance of said circuits alongsaid provisioned channel; (4) setting the end-to-end thresholds for saidprovisioned channel by assigning threshold levels at said one or moremonitoring points based upon said service provisioning request toindicate when said one or more monitoring points are required to reportan error or a potential occurrence of an error.
 2. The method of claim1, wherein step (2) further comprises the step of:submitting a requestto a network management application to retrieve the possible pathsbetween said termination points.
 3. The method of claim 1, wherein step(3) further comprises the steps of:(a) retrieving monitoring pointrequirements from. said service provisioning request; (b) identifyingthe location of monitoring points along said path topology.
 4. Themethod of claim 3, wherein step (b) comprises the steps of:locatingprimary monitoring points at or near the ends of said path topology orat network elements located at points of demarcation that distinguishthe facilities of an interexchange carrier from the facilities of alocal exchange carrier.
 5. The method of claim 3, wherein step (b)comprises the steps of:locating secondary monitoring points at networkelements located at intermediate positions along said path topology, andwherein the number of secondary monitoring points selected is based uponthe level of service provided in the service provisioning request. 6.The method of claim 1, wherein step (4) comprises:setting an end-to-endthreshold for said path topology based upon the location of saidtermination points and said level of service.
 7. The method of claim 1,comprising:setting said end-to-end threshold based upon the length ofcircuits comprising said provisioned channel.
 8. The method of claim 1,wherein each of said end-to-end thresholds reflects an acceptabletolerance in the quality of a service specified in said serviceprovisioning request.
 9. A system of setting end-to-end threshold levelsfor measuring and monitoring circuits in a telecommunications network,comprising:means for receiving a service provisioning requestidentifying termination points and a level of service identifying aquality of service desired by a customer; means for identifying a pathtopology for a provisioned channel between said termination points, saidprovisioned channel having said level of service; means for assigningone or more monitoring points for monitoring a performance of saidcircuits along said provisioned channel, if one or more monitoringpoints for monitoring a performance of said circuits have not beenpreassigned for said provisioned channel; means for setting theend-to-end thresholds for said provisioned channel by assigningthreshold levels at said one or more monitoring points based upon saidservice provisioning request to indicate when said one or moremonitoring points are required to report an error or a potentialoccurrence of an error.
 10. The system of claim 9, wherein said meansfor identifying a path topology further comprises:means for submitting arequest to a network management application to retrieve the possiblepaths between said termination points.
 11. The system of claim 9,wherein said means for assigning one or more monitoring points alongsaid provisioned channel further comprises:means for retrievingmonitoring point requirements from said service provisioning request;means for identifying the location of monitoring points along said pathtopology.
 12. The system of claim 11, wherein said means for identifyingthe location of monitoring points along said path topologycomprises:means for locating primary monitoring points at or near theends of said path topology or at network elements located at points ofdemarcation that distinguish the facilities of an interexchange carrierfrom the facilities of a local exchange carrier.
 13. The system of claim11, wherein said means for identifying the location of monitoring pointsalong said path topology comprises:means for locating secondarymonitoring points at network elements located at intermediate positionsalong said path topology, wherein the number of secondary monitoringpoints selected is based upon the level of service provided in theservice provisioning request.
 14. The system of claim 9, wherein saidmeans for setting end-to-end thresholds for said provisioned channelcomprises:means for setting an end-to-end threshold for said pathtopology based upon the location of said termination points and saidlevel of service.
 15. The system of claim 9, wherein said means forsetting end-to-end thresholds for said provisioned channelcomprises:means for setting said end-to-end threshold based upon thelength of circuits comprising said provisioned channel.
 16. The systemof claim 9, wherein each of said end-to-end thresholds reflects anacceptable tolerance in the quality of a service specified in saidservice provisioning request.